I'm referring to the jerk dip. Are you supposed to rely mainly on quads or are you supposed to squeeze the glutes?

my own experience:
If quad, then, of course, it will be the quad taking the load mostly. If glutes are flexed, the load will be shared among the glutes, quads and adductors. If I flex my glutes , my lumbar spine will go from the neutral arch to slightly rounded, with a posterior pelvic tilt as well.